Optical sensors are a widely employed method of measuring analyte concentration, typically oxygen, within a package or container. Briefly, analyte concentration within a package or container can be measured by placing an analyte sensitive fluorophore within the package or container, allowing the fluorophore to equilibrate within the package or container, exciting the fluorophore with radiant energy, and measuring the amount of luminescence emitted by the excite fluorophore. Such optical sensors are available from a number of suppliers, including Presens Precision Sensing, GmbH of Regensburg, Germany.
Such optical sensors are commonly programmed with a calibration mode that permits two-point calibration of the sensor by exposing the analyte sensitive fluorophore to gases having known concentrations of the analyte and sensing luminescence at these known concentrations of analyte (i.e., the fluorophore placed or inserted into a container that has been flushed with certified tank gas containing 0% analyte and luminescence measured, with the fluorophore then placed or inserted into a container that has been flushed with certified tank gas containing 90% analyte and luminescence measured).
While effective for accurately calibrating optical sensors, this calibration method is time consuming and expensive.
Accordingly, a substantial need exists for a low cost system and method for accurately and reliably calibrating an optical sensor.